There is one sense in which these two words have a similar meaning. What is the difference in this meaning, rather the difference in grammatical usage?

A assumes B

Smoke assumes fire.

This sentence doesn't work.

A implies B

Smoke implies fire.

If there is smoke, then there is a fire.

  • Flagging as general reference. See the FAQ for details. – bwDraco Apr 15 '13 at 14:12
  • @DragonLord Thank you for your diligence. For the purposes for closing, you should flag only for possible duplicate, migration, or off-topic (as well as the usual spam/offensive). It is for the community to decide if it is general reference, not the mods. – Kit Z. Fox Apr 15 '13 at 14:30

Assumptions are made by thinking beings. Things that cannot reason cannot make assumptions.

Implications are given by evidence.

Smoke assumes fire.

This makes no sense because smoke can't assume anything. It is not capable of reasoning.

Smoke implies fire.

This works because smoke is evidence of fire.

  • 1
    Yes - I believe OP is being misled by an allowed transferred meaning of presume rather than assume here: presume 2. To constitute reasonable evidence for assuming; appear to prove: A signed hotel bill presumes occupancy of a room. (AHD) – Edwin Ashworth Apr 15 '13 at 16:39
  • 2
    By this logic, one might suppose that to presuppose must take a sentient subject, but I see nothing odd about "smoke presupposes fire" – FumbleFingers Apr 15 '13 at 16:40
  • 1
    Close. Implications are actually made by propositions, not just evidence; implies is the usual English for the logical functor (truth table TFTT; pronounced 'horseshoe'; named "material implication"). There are also technical definitions for presupposition and entailment. – John Lawler Apr 15 '13 at 16:43
  • I think it works metonymically. – Mitch Apr 15 '13 at 18:53
  • Sorry, @Mitch, you've lost me there. – Matt E. Эллен Apr 15 '13 at 19:06

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